1
|
Li X, Li C, Zhang W, Wang Y, Qian P, Huang H. Inflammation and aging: signaling pathways and intervention therapies. Signal Transduct Target Ther 2023; 8:239. [PMID: 37291105 PMCID: PMC10248351 DOI: 10.1038/s41392-023-01502-8] [Citation(s) in RCA: 89] [Impact Index Per Article: 89.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2022] [Revised: 04/26/2023] [Accepted: 05/15/2023] [Indexed: 06/10/2023] Open
Abstract
Aging is characterized by systemic chronic inflammation, which is accompanied by cellular senescence, immunosenescence, organ dysfunction, and age-related diseases. Given the multidimensional complexity of aging, there is an urgent need for a systematic organization of inflammaging through dimensionality reduction. Factors secreted by senescent cells, known as the senescence-associated secretory phenotype (SASP), promote chronic inflammation and can induce senescence in normal cells. At the same time, chronic inflammation accelerates the senescence of immune cells, resulting in weakened immune function and an inability to clear senescent cells and inflammatory factors, which creates a vicious cycle of inflammation and senescence. Persistently elevated inflammation levels in organs such as the bone marrow, liver, and lungs cannot be eliminated in time, leading to organ damage and aging-related diseases. Therefore, inflammation has been recognized as an endogenous factor in aging, and the elimination of inflammation could be a potential strategy for anti-aging. Here we discuss inflammaging at the molecular, cellular, organ, and disease levels, and review current aging models, the implications of cutting-edge single cell technologies, as well as anti-aging strategies. Since preventing and alleviating aging-related diseases and improving the overall quality of life are the ultimate goals of aging research, our review highlights the critical features and potential mechanisms of inflammation and aging, along with the latest developments and future directions in aging research, providing a theoretical foundation for novel and practical anti-aging strategies.
Collapse
Affiliation(s)
- Xia Li
- Bone Marrow Transplantation Center, the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, People's Republic of China
- Liangzhu Laboratory, Zhejiang University Medical Center, 1369 West Wenyi Road, Hangzhou, 311121, China
- Institute of Hematology, Zhejiang University & Zhejiang Engineering Laboratory for Stem Cell and Immunotherapy, Hangzhou, 310058, China
- Zhejiang Province Engineering Laboratory for Stem Cell and Immunity Therapy, Hangzhou, 310058, China
| | - Chentao Li
- Liangzhu Laboratory, Zhejiang University Medical Center, 1369 West Wenyi Road, Hangzhou, 311121, China
- Zhejiang University-University of Edinburgh Institute, Zhejiang University School of Medicine, Zhejiang University, Haining, China
| | - Wanying Zhang
- Zhejiang University-University of Edinburgh Institute, Zhejiang University School of Medicine, Zhejiang University, Haining, China
| | - Yanan Wang
- Zhejiang University-University of Edinburgh Institute, Zhejiang University School of Medicine, Zhejiang University, Haining, China
| | - Pengxu Qian
- Liangzhu Laboratory, Zhejiang University Medical Center, 1369 West Wenyi Road, Hangzhou, 311121, China.
- Institute of Hematology, Zhejiang University & Zhejiang Engineering Laboratory for Stem Cell and Immunotherapy, Hangzhou, 310058, China.
- Zhejiang Province Engineering Laboratory for Stem Cell and Immunity Therapy, Hangzhou, 310058, China.
- Center for Stem Cell and Regenerative Medicine and Bone Marrow Transplantation Center of the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310058, China.
| | - He Huang
- Bone Marrow Transplantation Center, the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, People's Republic of China.
- Liangzhu Laboratory, Zhejiang University Medical Center, 1369 West Wenyi Road, Hangzhou, 311121, China.
- Institute of Hematology, Zhejiang University & Zhejiang Engineering Laboratory for Stem Cell and Immunotherapy, Hangzhou, 310058, China.
- Zhejiang Province Engineering Laboratory for Stem Cell and Immunity Therapy, Hangzhou, 310058, China.
| |
Collapse
|
2
|
Immune Memory in Aging: a Wide Perspective Covering Microbiota, Brain, Metabolism, and Epigenetics. Clin Rev Allergy Immunol 2021; 63:499-529. [PMID: 34910283 PMCID: PMC8671603 DOI: 10.1007/s12016-021-08905-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/24/2021] [Indexed: 11/06/2022]
Abstract
Non-specific innate and antigen-specific adaptive immunological memories are vital evolutionary adaptations that confer long-lasting protection against a wide range of pathogens. Adaptive memory is established by memory T and B lymphocytes following the recognition of an antigen. On the other hand, innate immune memory, also called trained immunity, is imprinted in innate cells such as macrophages and natural killer cells through epigenetic and metabolic reprogramming. However, these mechanisms of memory generation and maintenance are compromised as organisms age. Almost all immune cell types, both mature cells and their progenitors, go through age-related changes concerning numbers and functions. The aging immune system renders the elderly highly susceptible to infections and incapable of mounting a proper immune response upon vaccinations. Besides the increased infectious burden, older individuals also have heightened risks of metabolic and neurodegenerative diseases, which have an immunological component. This review discusses how immune function, particularly the establishment and maintenance of innate and adaptive immunological memory, regulates and is regulated by epigenetics, metabolic processes, gut microbiota, and the central nervous system throughout life, with a focus on old age. We explain in-depth how epigenetics and cellular metabolism impact immune cell function and contribute or resist the aging process. Microbiota is intimately linked with the immune system of the human host, and therefore, plays an important role in immunological memory during both homeostasis and aging. The brain, which is not an immune-isolated organ despite former opinion, interacts with the peripheral immune cells, and the aging of both systems influences the health of each other. With all these in mind, we aimed to present a comprehensive view of the aging immune system and its consequences, especially in terms of immunological memory. The review also details the mechanisms of promising anti-aging interventions and highlights a few, namely, caloric restriction, physical exercise, metformin, and resveratrol, that impact multiple facets of the aging process, including the regulation of innate and adaptive immune memory. We propose that understanding aging as a complex phenomenon, with the immune system at the center role interacting with all the other tissues and systems, would allow for more effective anti-aging strategies.
Collapse
|
3
|
|
4
|
Zhang Y, You X, Li S, Long Q, Zhu Y, Teng Z, Zeng Y. Peripheral Blood Leukocyte RNA-Seq Identifies a Set of Genes Related to Abnormal Psychomotor Behavior Characteristics in Patients with Schizophrenia. Med Sci Monit 2020; 26:e922426. [PMID: 32038049 PMCID: PMC7032534 DOI: 10.12659/msm.922426] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Schizophrenia is a multigene disease with a complex etiology and different clinical manifestations. It is of great significance to understand the etiology and pathogenesis of schizophrenia patients from different clinical dimensions and to interpret the potential molecular changes of schizophrenia patients from different clinical dimensions. MATERIAL AND METHODS RNA-Seq was performed on peripheral blood leukocytes of 50 patients with schizophrenia and 50 healthy controls. Phenotypic information of patients with schizophrenia was collected during blood sampling. Differentially expressed genes (DEGs) were screened by the edgeR package of R software. To better analyze the correlation between DEG expression values, explore the potential association between differential genes and clinical dimensions of schizophrenia, and identify hub genes, we constructed a DEG co-expression network using weighted gene co-expression network analysis (WGCNA). RESULTS We provide the transcription profiles of peripheral blood leukocytes in patients with schizophrenia and found a gene module (including 89 genes) closely related to the clinical dimension of abnormal psychomotor behavior in schizophrenia. CONCLUSIONS The findings enhance our understanding of the biological processes of schizophrenia, enabling us to identify specific clinical dimensions of genes for diagnosis and prognostic markers and possibly for targeted therapy.
Collapse
Affiliation(s)
- Yunqiao Zhang
- Sixth Affiliated Hospital, Kunming Medical University, Yuxi, Yunnan, China (mainland)
| | - Xu You
- Sixth Affiliated Hospital, Kunming Medical University, Yuxi, Yunnan, China (mainland)
| | - Siwu Li
- Key Laboratory of Animal Models and Human Disease Mechanisms of The Chinese Academy of Sciences and Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan, China (mainland)
| | - Qing Long
- Sixth Affiliated Hospital, Kunming Medical University, Yuxi, Yunnan, China (mainland)
| | - Yun Zhu
- Sixth Affiliated Hospital, Kunming Medical University, Yuxi, Yunnan, China (mainland)
| | - Zhaowei Teng
- Sixth Affiliated Hospital, Kunming Medical University, Yuxi, Yunnan, China (mainland)
| | - Yong Zeng
- Sixth Affiliated Hospital, Kunming Medical University, Yuxi, Yunnan, China (mainland)
| |
Collapse
|
5
|
Abstract
BACKGROUND Vitamin D deficiency is related to various cardiovascular diseases, including sudden cardiac arrest (SCA). This study investigated the association of vitamin D level with neurologic outcome and mortality after resuscitation from SCA. PATIENTS AND METHODS We enrolled patients who were successfully resuscitated from out-of-hospital cardiac arrest of presumed cardiac cause in Severance Cardiovascular Hospital as a prospective cohort registry. Baseline blood samples including pH, lactate, and vitamin D were obtained without fluid replacement just after hospital admission. Outcome was assessed by cerebral performance category (CPC) score at 1 month after SCA. Favorable outcome was defined as survival with CPC score of 1 or 2, whereas unfavorable one as death or survival with CPC scores of 3 through 5. Severe vitamin D deficiency was defined as 25(OH)D <10 ng/mL. RESULTS A total of 163 patients were included. Overall 96 (59%) patients had a favorable neurologic outcome, whereas 67 patients (41%) showed unfavorable outcome, including 37 (23%) mortality. Patients with unfavorable outcome were likely to be female and have initial non-shockable rhythm, longer arrest time, severe shock, diabetes, and baseline renal dysfunction. In multivariate analysis, severe vitamin D deficiency was one of the poor prognostic factors of both unfavorable neurologic outcome and mortality after SCA. CONCLUSIONS Vitamin D deficiency is very prevalent and strongly associated with both unfavorable neurologic outcome and mortality in patients resuscitated from SCA.
Collapse
|
6
|
Ativie F, Komorowska JA, Beins E, Albayram Ö, Zimmer T, Zimmer A, Tejera D, Heneka M, Bilkei-Gorzo A. Cannabinoid 1 Receptor Signaling on Hippocampal GABAergic Neurons Influences Microglial Activity. Front Mol Neurosci 2018; 11:295. [PMID: 30210289 PMCID: PMC6121063 DOI: 10.3389/fnmol.2018.00295] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Accepted: 08/03/2018] [Indexed: 12/17/2022] Open
Abstract
Microglia, the resident immune cells of the brain, play important roles in defending the brain against pathogens and supporting neuronal circuit plasticity. Chronic or excessive pro-inflammatory responses of microglia damage neurons, therefore their activity is tightly regulated. Pharmacological and genetic studies revealed that cannabinoid type 1 (CB1) receptor activity influences microglial activity, although microglial CB1 receptor expression is very low and activity-dependent. The CB1 receptor is mainly expressed on neurons in the central nervous system (CNS)-with an especially high level on GABAergic interneurons. Here, we determined whether CB1 signaling on this neuronal cell type plays a role in regulating microglial activity. We compared microglia density, morphology and cytokine expression in wild-type (WT) and GABAergic neuron-specific CB1 knockout mice (GABA/CB1-/-) under control conditions (saline-treatment) and after 3 h, 24 h or repeated lipopolysaccharide (LPS)-treatment. Our results revealed that hippocampal microglia from saline-treated GABA/CB1-/- mice resembled those of LPS-treated WT mice: enhanced density and larger cell bodies, while the size and complexity of their processes was reduced. No further reduction in the size or complexity of microglia branching was detected after LPS-treatment in GABA/CB1-/- mice, suggesting that microglia in naïve GABA/CB1-/- mice were already in an activated state. This result was further supported by correlating the level of microglial tumor necrosis factor α (TNFα) with their size. Acute LPS-treatment elicited in both genotypes similar changes in the expression of pro-inflammatory cytokines (TNFα, interleukin-6 (IL-6) and interleukin 1β (IL-1β)). However, TNFα expression was still significantly elevated after repeated LPS-treatment in WT, but not in GABA/CB1-/- mice, indicating a faster development of tolerance to LPS. We also tested the possibility that the altered microglia activity in GABA/CB1-/- mice was due to an altered expression of neuron-glia interaction proteins. Indeed, the level of fractalkine (CX3CL1), a neuronal protein involved in the regulation of microglia, was reduced in hippocampal GABAergic neurons in GABA/CB1-/- mice, suggesting a disturbed neuronal control of microglial activity. Our result suggests that CB1 receptor agonists can modulate microglial activity indirectly, through CB1 receptors on GABAergic neurons. Altogether, we demonstrated that GABAergic neurons, despite their relatively low density in the hippocampus, have a specific role in the regulation of microglial activity and cannabinoid signaling plays an important role in this arrangement.
Collapse
Affiliation(s)
- Frank Ativie
- Institute of Molecular Psychiatry, Medical Faculty, University of Bonn, Bonn, Germany
| | - Joanna A Komorowska
- Institute of Molecular Psychiatry, Medical Faculty, University of Bonn, Bonn, Germany
| | - Eva Beins
- Institute of Molecular Psychiatry, Medical Faculty, University of Bonn, Bonn, Germany
| | - Önder Albayram
- Institute of Molecular Psychiatry, Medical Faculty, University of Bonn, Bonn, Germany
| | - Till Zimmer
- Institute of Molecular Psychiatry, Medical Faculty, University of Bonn, Bonn, Germany
| | - Andreas Zimmer
- Institute of Molecular Psychiatry, Medical Faculty, University of Bonn, Bonn, Germany
| | - Dario Tejera
- Department of Neurodegenerative Diseases & Gerontopsychiatry, Medical Faculty, University of Bonn, Bonn, Germany
| | - Michael Heneka
- Department of Neurodegenerative Diseases & Gerontopsychiatry, Medical Faculty, University of Bonn, Bonn, Germany
| | - Andras Bilkei-Gorzo
- Institute of Molecular Psychiatry, Medical Faculty, University of Bonn, Bonn, Germany
| |
Collapse
|
7
|
Coder B, Wang W, Wang L, Wu Z, Zhuge Q, Su DM. Friend or foe: the dichotomous impact of T cells on neuro-de/re-generation during aging. Oncotarget 2018; 8:7116-7137. [PMID: 27738345 PMCID: PMC5351694 DOI: 10.18632/oncotarget.12572] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Accepted: 10/05/2016] [Indexed: 12/15/2022] Open
Abstract
The interaction between T cells and the central nervous system (CNS) in homeostasis and injury has been recognized being both pathogenic (CD4+ T-helper 1 - Th1, Th17 and γδT) and ameliorative (Th2 and regulatory T cells - Tregs). However, in-depth studies aimed to elucidate the precise in the aged microenvironment and the dichotomous role of Tregs have just begun and many aspects remain unclear. This is due, not only to a mutual dependency and reciprocal causation of alterations and diseases between the nervous and T cell immune systems, but also to an inconsistent aging of the two systems, which dynamically changes with CNS injury/recovery and/or aging process. Cellular immune system aging, particularly immunosenescence and T cell aging initiated by thymic involution - sources of chronic inflammation in the elderly (termed inflammaging), potentially induces an acceleration of brain aging and memory loss. In turn, aging of the brain via neuro-endocrine-immune network drives total body systemic aging, including that of the immune system. Therefore, immunotherapeutics including vaccination and “protective autoimmunity” provide promising means to rejuvenate neuro-inflammatory disorders and repair CNS acute injury and chronic neuro-degeneration. We review the current understanding and recent discoveries linking the aging immune system with CNS injury and neuro-degeneration. Additionally, we discuss potential recovery and rejuvenation strategies, focusing on targeting the aging T cell immune system in an effort to alleviate acute brain injury and chronic neuro-degeneration during aging, via the “thymus-inflammaging-neurodegeneration axis”.
Collapse
Affiliation(s)
- Brandon Coder
- Institute of Molecular Medicine, University of North Texas Health Science Center, Fort Worth, TX, USA
| | - Weikan Wang
- Institute of Molecular Medicine, University of North Texas Health Science Center, Fort Worth, TX, USA.,Zhejiang Provincial Key Laboratory of Aging and Neurological Disease Research, First Affiliated Hospital, Wenzhou Medical University, Wenzhou City, Zhejiang, P. R. China
| | - Liefeng Wang
- Institute of Molecular Medicine, University of North Texas Health Science Center, Fort Worth, TX, USA.,Department of Biotechnology, Gannan Medical University, Ganzhou, P. R. China
| | - Zhongdao Wu
- Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, P. R. China
| | - Qichuan Zhuge
- Zhejiang Provincial Key Laboratory of Aging and Neurological Disease Research, First Affiliated Hospital, Wenzhou Medical University, Wenzhou City, Zhejiang, P. R. China
| | - Dong-Ming Su
- Institute of Molecular Medicine, University of North Texas Health Science Center, Fort Worth, TX, USA
| |
Collapse
|
8
|
Wen L, Zhang QS, Heng Y, Chen Y, Wang S, Yuan YH, Chen NH. NLRP3 inflammasome activation in the thymus of MPTP-induced Parkinsonian mouse model. Toxicol Lett 2018; 288:1-8. [PMID: 29421335 DOI: 10.1016/j.toxlet.2018.02.003] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Accepted: 02/03/2018] [Indexed: 10/18/2022]
Abstract
Ample evidence shows that Parkinson's disease (PD) is more than simply a central nervous system (CNS) disorder: the immune system appears to participate in PD pathogenesis. Extracellular misfolded α-synuclein (α-syn) may trigger an inflammatory response in the brain. Abnormal immune responses are involved in the development of PD, but little is known about the relationship between the thymus malfunction and the pathogenesis of PD. The present study investigated 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced impairment in thymus and explored possible mechanisms involved in PD pathogenesis. After subcutaneous injection of MPTP (25 mg/kg) every 4 days for 40-days, immune responses became unbalanced, with increased IL-1β concentrations. On histopathology, mice treated with MPTP displayed pathological involution and damaged ultrastructure of the thymus. Both the PD-related oligomeric α-synuclein and oxidative stress related nitrated-α-synuclein (Tyr125, Tyr133) in mice treated with MPTP were elevated. Correspondingly, oxidative stress damage was detected in the form of increased 8-hydroxyguanosine staining. Moreover, MPTP significantly increased expression of caspase-8, NF-κB, NLPR3, and caspase-1 in the thymus. These results suggested that MPTP was toxic to mouse thymus via a mechanism involving the NF-κB and NLRP3 inflammasome pathway. These results suggested that environmental factors may lead to pathological changes in the thymus that are similar to those in the central nervous system. A disordered thymus might take part in the development of PD, and its enhanced immune response might promote the degenerative changes in the brain.
Collapse
Affiliation(s)
- Lu Wen
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| | - Qiu-Shuang Zhang
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| | - Yang Heng
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| | - Ying Chen
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| | - Shuo Wang
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China
| | - Yu-He Yuan
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China.
| | - Nai-Hong Chen
- State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica & Neuroscience Center, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China; College of Pharmacy, Hunan University of Chinese Medicine, Changsha, Hunan 410208, China.
| |
Collapse
|
9
|
Smith LK, White CW, Villeda SA. The systemic environment: at the interface of aging and adult neurogenesis. Cell Tissue Res 2017; 371:105-113. [PMID: 29124393 PMCID: PMC5748432 DOI: 10.1007/s00441-017-2715-8] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Accepted: 10/09/2017] [Indexed: 02/06/2023]
Abstract
Aging results in impaired neurogenesis in the two neurogenic niches of the adult mammalian brain, the dentate gyrus of the hippocampus and the subventricular zone of the lateral ventricle. While significant work has characterized intrinsic cellular changes that contribute to this decline, it is increasingly apparent that the systemic environment also represents a critical driver of brain aging. Indeed, emerging studies utilizing the model of heterochronic parabiosis have revealed that immune-related molecular and cellular changes in the aging systemic environment negatively regulate adult neurogenesis. Interestingly, these studies have also demonstrated that age-related decline in neurogenesis can be ameliorated by exposure to the young systemic environment. While this burgeoning field of research is increasingly garnering interest, as yet, the precise mechanisms driving either the pro-aging effects of aged blood or the rejuvenating effects of young blood remain to be thoroughly defined. Here, we review how age-related changes in blood, blood-borne factors, and peripheral immune cells contribute to the age-related decline in adult neurogenesis in the mammalian brain, and posit both direct neural stem cell and indirect neurogenic niche-mediated mechanisms.
Collapse
Affiliation(s)
- Lucas K Smith
- Department of Anatomy, University of California, San Francisco, San Francisco, CA, 94143, USA.,The Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California San Francisco, San Francisco, CA, 94143, USA.,Biomedical Sciences Graduate Program, University of California San Francisco, San Francisco, CA, 94143, USA
| | - Charles W White
- Department of Anatomy, University of California, San Francisco, San Francisco, CA, 94143, USA.,The Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California San Francisco, San Francisco, CA, 94143, USA.,Developmental and Stem Cell Biology Graduate Program, University of California San Francisco, San Francisco, CA, 94143, USA
| | - Saul A Villeda
- Department of Anatomy, University of California, San Francisco, San Francisco, CA, 94143, USA. .,The Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California San Francisco, San Francisco, CA, 94143, USA. .,Biomedical Sciences Graduate Program, University of California San Francisco, San Francisco, CA, 94143, USA. .,Developmental and Stem Cell Biology Graduate Program, University of California San Francisco, San Francisco, CA, 94143, USA.
| |
Collapse
|
10
|
Nataf S. Autoimmunity as a Driving Force of Cognitive Evolution. Front Neurosci 2017; 11:582. [PMID: 29123465 PMCID: PMC5662758 DOI: 10.3389/fnins.2017.00582] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Accepted: 10/04/2017] [Indexed: 12/12/2022] Open
Abstract
In the last decades, increasingly robust experimental approaches have formally demonstrated that autoimmunity is a physiological process involved in a large range of functions including cognition. On this basis, the recently enunciated “brain superautoantigens” theory proposes that autoimmunity has been a driving force of cognitive evolution. It is notably suggested that the immune and nervous systems have somehow co-evolved and exerted a mutual selection pressure benefiting to both systems. In this two-way process, the evolutionary-determined emergence of neurons expressing specific immunogenic antigens (brain superautoantigens) has exerted a selection pressure on immune genes shaping the T-cell repertoire. Such a selection pressure on immune genes has translated into the emergence of a finely tuned autoimmune T-cell repertoire that promotes cognition. In another hand, the evolutionary-determined emergence of brain-autoreactive T-cells has exerted a selection pressure on neural genes coding for brain superautoantigens. Such a selection pressure has translated into the emergence of a neural repertoire (defined here as the whole of neurons, synapses and non-neuronal cells involved in cognitive functions) expressing brain superautoantigens. Overall, the brain superautoantigens theory suggests that cognitive evolution might have been primarily driven by internal cues rather than external environmental conditions. Importantly, while providing a unique molecular connection between neural and T-cell repertoires under physiological conditions, brain superautoantigens may also constitute an Achilles heel responsible for the particular susceptibility of Homo sapiens to “neuroimmune co-pathologies” i.e., disorders affecting both neural and T-cell repertoires. These may notably include paraneoplastic syndromes, multiple sclerosis as well as autism, schizophrenia and neurodegenerative diseases. In the context of this theoretical frame, a specific emphasis is given here to the potential evolutionary role exerted by two families of genes, namely the MHC class II genes, involved in antigen presentation to T-cells, and the Foxp genes, which play crucial roles in language (Foxp2) and the regulation of autoimmunity (Foxp3).
Collapse
Affiliation(s)
- Serge Nataf
- CarMeN Laboratory, Bank of Tissues and Cells, Institut National de la Santé et de la Recherche Médicale 1060, INRA 1397, INSA Lyon, Lyon University Hospital (Hospices Civils de Lyon), Université Claude Bernard Lyon-1, Lyon, France
| |
Collapse
|
11
|
Impact of aging immune system on neurodegeneration and potential immunotherapies. Prog Neurobiol 2017; 157:2-28. [PMID: 28782588 DOI: 10.1016/j.pneurobio.2017.07.006] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Revised: 07/25/2017] [Accepted: 07/28/2017] [Indexed: 12/19/2022]
Abstract
The interaction between the nervous and immune systems during aging is an area of avid interest, but many aspects remain unclear. This is due, not only to the complexity of the aging process, but also to a mutual dependency and reciprocal causation of alterations and diseases between both the nervous and immune systems. Aging of the brain drives whole body systemic aging, including aging-related changes of the immune system. In turn, the immune system aging, particularly immunosenescence and T cell aging initiated by thymic involution that are sources of chronic inflammation in the elderly (termed inflammaging), potentially induces brain aging and memory loss in a reciprocal manner. Therefore, immunotherapeutics including modulation of inflammation, vaccination, cellular immune therapies and "protective autoimmunity" provide promising approaches to rejuvenate neuroinflammatory disorders and repair brain injury. In this review, we summarize recent discoveries linking the aging immune system with the development of neurodegeneration. Additionally, we discuss potential rejuvenation strategies, focusing aimed at targeting the aging immune system in an effort to prevent acute brain injury and chronic neurodegeneration during aging.
Collapse
|
12
|
Cascella M, Bimonte S. The role of general anesthetics and the mechanisms of hippocampal and extra-hippocampal dysfunctions in the genesis of postoperative cognitive dysfunction. Neural Regen Res 2017; 12:1780-1785. [PMID: 29239315 PMCID: PMC5745823 DOI: 10.4103/1673-5374.219032] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Postoperative cognitive dysfunction (POCD) is a multifactorial process with a huge number of predisposing, causal, and precipitating factors. In this scenario, the neuroinflammation and the microglial activation play a pivotal role by triggering and amplifying a complex cascade involving the immuno-hormonal activation, the micro circle alterations, the hippocampal oxidative stress activation and, finally, an increased blood-brain barrier's permeability. While the role of anesthetics in the POCD's genesis in humans is debated, a huge number of preclinical studies have been conducted on the topic and many mechanisms have been proposed to explain the potential neurodegenerative effects of general anesthetics. Probably, the problem concerns on what we are searching for and how we are searching and, surprisingly, preclinical studies showed that anesthetics may also manifest neuroprotective properties. The aim of this paper is to offer an overview on the potential impact of general anesthetics on POCD. Mechanisms of hippocampal and extra-hippocampal dysfunction due to neuroinflammation are discussed, whereas further research perspectives are also given.
Collapse
Affiliation(s)
- Marco Cascella
- Division of Anesthesia and Pain Medicine, Istituto Nazionale Tumori - IRCCS - Fondazione G. Pascale, Via Mariano Semmola, Naples, Italy
| | - Sabrina Bimonte
- Division of Anesthesia and Pain Medicine, Istituto Nazionale Tumori - IRCCS - Fondazione G. Pascale, Via Mariano Semmola, Naples, Italy
| |
Collapse
|
13
|
Hoeijmakers L, Heinen Y, van Dam AM, Lucassen PJ, Korosi A. Microglial Priming and Alzheimer's Disease: A Possible Role for (Early) Immune Challenges and Epigenetics? Front Hum Neurosci 2016; 10:398. [PMID: 27555812 PMCID: PMC4977314 DOI: 10.3389/fnhum.2016.00398] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Accepted: 07/26/2016] [Indexed: 12/11/2022] Open
Abstract
Neuroinflammation is thought to contribute to Alzheimer's disease (AD) pathogenesis that is, to a large extent, mediated by microglia. Given the tight interaction between the immune system and the brain, peripheral immune challenges can profoundly affect brain function. Indeed, both preclinical and clinical studies have indicated that an aberrant inflammatory response can elicit behavioral impairments and cognitive deficits, especially when the brain is in a vulnerable state, e.g., during early development, as a result of aging, or under disease conditions like AD. However, how exactly peripheral immune challenges affect brain function and whether this is mediated by aberrant microglial functioning remains largely elusive. In this review, we hypothesize that: (1) systemic immune challenges occurring during vulnerable periods of life can increase the propensity to induce later cognitive dysfunction and accelerate AD pathology; and (2) that "priming" of microglial cells is instrumental in mediating this vulnerability. We highlight how microglia can be primed by both neonatal infections as well as by aging, two periods of life during which microglial activity is known to be specifically upregulated. Lasting changes in (the ratios of) specific microglial phenotypes can result in an exaggerated pro-inflammatory cytokine response to subsequent inflammatory challenges. While the resulting changes in brain function are initially transient, a continued and/or excess release of such pro-inflammatory cytokines can activate various downstream cellular cascades known to be relevant for AD. Finally, we discuss microglial priming and the aberrant microglial response as potential target for treatment strategies for AD.
Collapse
Affiliation(s)
- Lianne Hoeijmakers
- Swammerdam Institute for Life Sciences, Center for Neuroscience, University of Amsterdam Amsterdam, Netherlands
| | - Yvonne Heinen
- Swammerdam Institute for Life Sciences, Center for Neuroscience, University of Amsterdam Amsterdam, Netherlands
| | - Anne-Marie van Dam
- Department of Anatomy and Neurosciences, Neuroscience Campus Amsterdam, VU University Medical Center Amsterdam, Netherlands
| | - Paul J Lucassen
- Swammerdam Institute for Life Sciences, Center for Neuroscience, University of Amsterdam Amsterdam, Netherlands
| | - Aniko Korosi
- Swammerdam Institute for Life Sciences, Center for Neuroscience, University of Amsterdam Amsterdam, Netherlands
| |
Collapse
|
14
|
Wang F, Shen X, Li S, Chen L, Wang Y, Qin J, Zhou G, Peng Y, Feng X, Li R, Liang C. Splenocytes derived from young WT mice prevent AD progression in APPswe/PSENldE9 transgenic mice. Oncotarget 2016; 6:20851-62. [PMID: 26317549 PMCID: PMC4673234 DOI: 10.18632/oncotarget.4930] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Accepted: 07/24/2015] [Indexed: 12/28/2022] Open
Abstract
Immunosenescence contributes to pathogenesis of Alzheimer's disease (AD) in the elderly. In this study, we explored the effects of young wild type (WT) splenocytes (ySCs) on Alzheimer's disease by transplanting ySCs into APPswe/PSENldE9 transgenic mice. Young WT splenocytes not only prevented AD, but also improved the spatial learning and memory of APPswe/PSENldE9 transgenic mice. Young WT splenocytes enhanced Aβ clearance, decreased astrogliosis and increased systemic growth differentiation factor 11 (GDF11) levels. Splenocytes derived from old AD mouse promoted AD. There was an increased number of regulatory T cells (Tregs) among old AD splenocytes. We suggest that alterations of GDF11 and Tregs are involved in AD progression and that rejuvenation of the immune system is a potential therapeutic strategy in AD.
Collapse
Affiliation(s)
- Fei Wang
- Department of Anatomy and Histology & Embryology, Shanghai Medical College of Fudan University, Shanghai, P. R. China
| | - Xueyan Shen
- Department of Anatomy and Histology & Embryology, Shanghai Medical College of Fudan University, Shanghai, P. R. China
| | - Shuping Li
- Department of Radiology, Huashan Hospital, Fudan University, Shanghai, P. R. China.,Department of Radiology, PLA No. 455 Hospital, Shanghai, P. R. China
| | - Long Chen
- Department of Anatomy and Histology & Embryology, Shanghai Medical College of Fudan University, Shanghai, P. R. China
| | - Yanru Wang
- Department of Anatomy and Histology & Embryology, Shanghai Medical College of Fudan University, Shanghai, P. R. China
| | - Jie Qin
- Department of Anatomy and Histology & Embryology, Shanghai Medical College of Fudan University, Shanghai, P. R. China
| | - Guomin Zhou
- Department of Anatomy and Histology & Embryology, Shanghai Medical College of Fudan University, Shanghai, P. R. China
| | - Yuwen Peng
- Department of Anatomy and Histology & Embryology, Shanghai Medical College of Fudan University, Shanghai, P. R. China
| | - Xiaoyuan Feng
- Department of Radiology, Huashan Hospital, Fudan University, Shanghai, P. R. China
| | - Ruixi Li
- Department of Anatomy and Histology & Embryology, Shanghai Medical College of Fudan University, Shanghai, P. R. China
| | - Chunmin Liang
- Department of Anatomy and Histology & Embryology, Shanghai Medical College of Fudan University, Shanghai, P. R. China
| |
Collapse
|
15
|
Deczkowska A, Baruch K, Schwartz M. Type I/II Interferon Balance in the Regulation of Brain Physiology and Pathology. Trends Immunol 2016; 37:181-192. [PMID: 26877243 DOI: 10.1016/j.it.2016.01.006] [Citation(s) in RCA: 83] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Revised: 01/11/2016] [Accepted: 01/12/2016] [Indexed: 12/11/2022]
Abstract
Recent findings have revealed distinct roles for type I and II interferons (IFN-I and IFN-γ) in the recruitment of immune cells to the central nervous system (CNS) and highlighted the importance of this process for brain maintenance and protection/repair. Furthermore, manipulation of IFN-I and IFN-γ pathways in pathological contexts has yielded conflicting results. We discuss these findings, focusing on two distinct conditions; relapsing remitting multiple sclerosis (RRMS) and brain aging. Using these examples, we propose that regulation of immune cell entry to the CNS is a mechanism through which interaction between IFN-I and -II can affect brain function from its anatomical borders. Deviation from homeostatic IFN-I/-II balance may contribute to distinct brain pathologies, resulting from either insufficient immune surveillance of the CNS and loss of immune-dependent protection, or overwhelming leukocyte entry and immune-mediated destruction.
Collapse
Affiliation(s)
| | - Kuti Baruch
- Department of Neurobiology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Michal Schwartz
- Department of Neurobiology, Weizmann Institute of Science, Rehovot 7610001, Israel.
| |
Collapse
|
16
|
Yalbuzdag SA, Sarifakioglu B, Afsar SI, Celik C, Can A, Yegin T, Senturk B, Guzelant AY. Is 25(OH)D Associated with Cognitive Impairment and Functional Improvement in Stroke? A Retrospective Clinical Study. J Stroke Cerebrovasc Dis 2015; 24:1479-86. [PMID: 25922112 DOI: 10.1016/j.jstrokecerebrovasdis.2015.03.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2014] [Revised: 03/02/2015] [Accepted: 03/08/2015] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND In recent years, vitamin D deficiency has been suggested as a risk factor for ischemic stroke and stroke severity in both animal models and clinical studies. In this retrospective study, we investigated the relationship between 25-hydroxyvitamin D [25(OH)D] levels and functional outcomes in stroke patients during neurological rehabilitation program. We also investigated whether there is an association between 25(OH)D levels and cognitive impairment. METHODS The study included the medical records of 120 stroke patients who participated in a neurological rehabilitation program. The motor and cognitive components of the Functional Independence Measurements of all patients at admission and discharge were recorded. The Functional Ambulatory Scale was used to assess motor functional status, and the Turkish-validated version of the minimental state examination test was used to assess cognitive status. RESULTS A significant correlation was found between 25(OH)D level and cognitive impairment among patients who had ischemic strokes. High levels of 25(OH)D were associated with greater functional gain during the rehabilitation program in both ischemic stroke patients and hemorrhagic stroke patients. CONCLUSIONS High 25(OH)D levels might be associated with greater functional improvement and with less cognitive impairment in stroke patients.
Collapse
Affiliation(s)
- Seniz Akcay Yalbuzdag
- Physical Medicine and Rehabilitation Department, Izmir Bozyaka Education and Research Hospital, Izmir, Turkey.
| | - Banu Sarifakioglu
- Physical Medicine and Rehabilitation Department, Namık Kemal University, Tekirdag, Turkey
| | - Sevgi Ikbali Afsar
- Physical Medicine and Rehabilitation Department, Baskent University, Ankara, Turkey
| | - Canan Celik
- Physical Medicine and Rehabilitation Department, Sevket Yilmaz Education and Research Hospital, Bursa, Turkey
| | - Aslı Can
- Physical Medicine and Rehabilitation Department, Ankara Diskapi Education and Research Hospital, Ankara, Turkey
| | - Tugba Yegin
- Physical Medicine and Rehabilitation Department, Sevket Yilmaz Education and Research Hospital, Bursa, Turkey
| | - Burcu Senturk
- Physical Medicine and Rehabilitation Department, Sevket Yilmaz Education and Research Hospital, Bursa, Turkey
| | | |
Collapse
|
17
|
Baruch K, Deczkowska A, David E, Castellano JM, Miller O, Kertser A, Berkutzki T, Barnett-Itzhaki Z, Bezalel D, Wyss-Coray T, Amit I, Schwartz M. Aging. Aging-induced type I interferon response at the choroid plexus negatively affects brain function. Science 2014; 346:89-93. [PMID: 25147279 PMCID: PMC4869326 DOI: 10.1126/science.1252945] [Citation(s) in RCA: 416] [Impact Index Per Article: 41.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Aging-associated cognitive decline is affected by factors produced inside and outside the brain. By using multiorgan genome-wide analysis of aged mice, we found that the choroid plexus, an interface between the brain and the circulation, shows a type I interferon (IFN-I)-dependent gene expression profile that was also found in aged human brains. In aged mice, this response was induced by brain-derived signals, present in the cerebrospinal fluid. Blocking IFN-I signaling within the aged brain partially restored cognitive function and hippocampal neurogenesis and reestablished IFN-II-dependent choroid plexus activity, which is lost in aging. Our data identify a chronic aging-induced IFN-I signature, often associated with antiviral response, at the brain's choroid plexus and demonstrate its negative influence on brain function, thereby suggesting a target for ameliorating cognitive decline in aging.
Collapse
Affiliation(s)
- Kuti Baruch
- Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Israel
| | | | - Eyal David
- Department of Immunology, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Joseph M Castellano
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Omer Miller
- Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Alexander Kertser
- Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Tamara Berkutzki
- Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Israel
| | | | - Dana Bezalel
- Department of Immunology, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Tony Wyss-Coray
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Ido Amit
- Department of Immunology, Weizmann Institute of Science, Rehovot 76100, Israel.
| | - Michal Schwartz
- Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Israel.
| |
Collapse
|
18
|
Baruch K, Schwartz M. CNS-specific T cells shape brain function via the choroid plexus. Brain Behav Immun 2013; 34:11-6. [PMID: 23597431 DOI: 10.1016/j.bbi.2013.04.002] [Citation(s) in RCA: 132] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2013] [Revised: 04/07/2013] [Accepted: 04/08/2013] [Indexed: 12/17/2022] Open
Abstract
Adaptive immunity was repeatedly shown to play a role in maintaining lifelong brain function. Under physiological conditions, this activity was associated with CD4+ T cells specific for brain self-antigens. Nevertheless, direct interactions of T cells with the healthy neuronal parenchyma are hardly detectable. Recent studies have identified the brain's choroid plexus (CP) as an active neuro-immunological interface, enriched with CNS-specific CD4+ T cells. Strategically positioned for receiving signals from both the central nervous system (CNS) through the cerebrospinal fluid (CSF), and from the circulation through epithelium-immune cell interactions, the CP has recently been recognized as an important immunological compartment in maintaining and restoring brain homeostasis/allostasis. Here, we propose that CNS-specific T cells shape brain function via the CP, and suggest this immunological control to be lost as part of aging, in general, and immune senescence, in particular. Accordingly, the CP may serve as a novel target for immunomodulation to restore brain equilibrium.
Collapse
Affiliation(s)
- Kuti Baruch
- Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Israel
| | | |
Collapse
|
19
|
Bilkei-Gorzo A. The endocannabinoid system in normal and pathological brain ageing. Philos Trans R Soc Lond B Biol Sci 2013; 367:3326-41. [PMID: 23108550 DOI: 10.1098/rstb.2011.0388] [Citation(s) in RCA: 92] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The role of endocannabinoids as inhibitory retrograde transmitters is now widely known and intensively studied. However, endocannabinoids also influence neuronal activity by exerting neuroprotective effects and regulating glial responses. This review centres around this less-studied area, focusing on the cellular and molecular mechanisms underlying the protective effect of the cannabinoid system in brain ageing. The progression of ageing is largely determined by the balance between detrimental, pro-ageing, largely stochastic processes, and the activity of the homeostatic defence system. Experimental evidence suggests that the cannabinoid system is part of the latter system. Cannabinoids as regulators of mitochondrial activity, as anti-oxidants and as modulators of clearance processes protect neurons on the molecular level. On the cellular level, the cannabinoid system regulates the expression of brain-derived neurotrophic factor and neurogenesis. Neuroinflammatory processes contributing to the progression of normal brain ageing and to the pathogenesis of neurodegenerative diseases are suppressed by cannabinoids, suggesting that they may also influence the ageing process on the system level. In good agreement with the hypothesized beneficial role of cannabinoid system activity against brain ageing, it was shown that animals lacking CB1 receptors show early onset of learning deficits associated with age-related histological and molecular changes. In preclinical models of neurodegenerative disorders, cannabinoids show beneficial effects, but the clinical evidence regarding their efficacy as therapeutic tools is either inconclusive or still missing.
Collapse
|
20
|
Sohrabji F, Selvamani A, Balden R. Revisiting the timing hypothesis: biomarkers that define the therapeutic window of estrogen for stroke. Horm Behav 2013; 63:222-30. [PMID: 22728278 PMCID: PMC3483414 DOI: 10.1016/j.yhbeh.2012.06.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2012] [Revised: 06/11/2012] [Accepted: 06/12/2012] [Indexed: 02/06/2023]
Abstract
Significantly extended life expectancy coupled with contemporary sedentary lifestyles and poor nutrition has created a global epidemic of cardiovascular disease and stroke. For women, this issue is complicated by the discrepant outcomes of hormone therapy (HT) for stroke incidence and severity as well as the therapeutic complications for stroke associated with advancing age. Here we propose that the impact of estrogen therapy cannot be considered in isolation, but should include age-related changes in endocrine, immune, and nucleic acid mediators that collaborate with estrogen to produce neuroprotective effects commonly seen in younger, healthier demographics. Due to their role as modulators of ischemic cell death, the post-stroke inflammatory response, and neuronal survival and regeneration, this review proposes that Insulin-like Growth Factor (IGF)-1, Vitamin D, and discrete members of the family of non-coding RNA peptides called microRNAs (miRNAs) may be crucial biochemical markers that help determine the neuroprotective "window" of HT. Specifically, IGF-1 confers neuroprotection in concert with, and independently of, estrogen and failure of the insulin/IGF-1 axis is associated with metabolic disturbances that increase the risk for stroke. Vitamin D and miRNAs regulate and complement IGF-1 mediated function and neuroprotective efficacy via modulation of IGF-1 availability and neural stem cell and immune cell proliferation, differentiation and secretions. Together, age-related decline of these factors differentially affects stroke risk, severity, and outcome, and may provide a novel therapeutic adjunct to traditional HT practices.
Collapse
Affiliation(s)
- Farida Sohrabji
- Department of Neuroscience and Experimental Therapeutics, Women's Health in Neuroscience Program, Texas A&M Health Science Center, College Station, TX 77843-1114, USA.
| | | | | |
Collapse
|
21
|
Hülür G, Infurna FJ, Ram N, Gerstorf D. Cohorts based on decade of death: no evidence for secular trends favoring later cohorts in cognitive aging and terminal decline in the AHEAD study. Psychol Aging 2012; 28:115-27. [PMID: 23046001 DOI: 10.1037/a0029965] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Studies of birth-year cohorts examined over the same age range often report secular trends favoring later-born cohorts, who are cognitively fitter and show less steep cognitive declines than earlier-born cohorts. However, there is initial evidence that those advantages of later-born cohorts do not carry into the last years of life, suggesting that pervasive mortality-related processes minimize differences that were apparent earlier in life. Elaborating this work from an alternative perspective on cohort differences, we compared rates of cognitive aging and terminal decline in episodic memory between cohorts based on the year participants had died, earlier (between 1993 and 1999) or later in historical time (between 2000 and 2010). Specifically, we compared trajectories of cognitive decline in 2 death-year cohorts of participants in the Asset and Health Dynamics Among the Oldest Old study that were matched on age at death and education and controlled for a variety of additional covariates. Results revealed little evidence of secular trends favoring later cohorts. To the contrary, the cohort that died in the 2000s showed a less favorable trajectory of age-related memory decline than the cohort that died in the 1990s. In examinations of change in relation to time to death, the cohort dying in the 2000s experienced even steeper terminal declines than the cohort dying in the 1990s. We suggest that secular increases in "manufacturing" survival may exacerbate age- and mortality-related cognitive declines among the oldest old.
Collapse
Affiliation(s)
- Gizem Hülür
- Institute of Psychology, Humboldt University, Berlin, Germany.
| | | | | | | |
Collapse
|
22
|
Balden R, Selvamani A, Sohrabji F. Vitamin D deficiency exacerbates experimental stroke injury and dysregulates ischemia-induced inflammation in adult rats. Endocrinology 2012; 153:2420-35. [PMID: 22408173 PMCID: PMC3339639 DOI: 10.1210/en.2011-1783] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Vitamin D deficiency (VDD) is widespread and considered a risk factor for cardiovascular disease and stroke. Low vitamin D levels are predictive for stroke and more fatal strokes in humans, whereas vitamin D supplements are associated with decreased risk of all-cause mortality. Because VDD occurs with other comorbid conditions that are also independent risk factors for stroke, this study examined the specific effect of VDD on stroke severity in rats. Adult female rats were fed control or VDD diet for 8 wk and were subject to middle cerebral artery occlusion thereafter. The VDD diet reduced circulating vitamin D levels to one fifth (22%) of that observed in rats fed control chow. Cortical and striatal infarct volumes in animals fed VDD diet were significantly larger, and sensorimotor behavioral testing indicated that VDD animals had more severe poststroke behavioral impairment than controls. VDD animals were also found to have significantly lower levels of the neuroprotective hormone IGF-I in plasma and the ischemic hemisphere. Cytokine analysis indicated that VDD significantly reduced IL-1α, IL-1β, IL-2, IL-4, IFN-γ, and IL-10 expression in ischemic brain tissue. However, ischemia-induced IL-6 up-regulation was significantly higher in VDD animals. In a separate experiment, the therapeutic potential of acute vitamin D treatments was evaluated, where animals received vitamin D injections 4 h after stroke and every 24 h thereafter. Acute vitamin D treatment did not improve infarct volume or behavioral performance. Our data indicate that VDD exacerbates stroke severity, involving both a dysregulation of the inflammatory response as well as suppression of known neuroprotectants such as IGF-I.
Collapse
Affiliation(s)
- Robyn Balden
- Department of Neuroscience and Experimental Therapeutics, Texas A&M Health Science Center, 228 Reynolds Medical Building, College Station, Texas 77843-1114, USA
| | | | | |
Collapse
|
23
|
Martino G, Pluchino S, Bonfanti L, Schwartz M. Brain regeneration in physiology and pathology: the immune signature driving therapeutic plasticity of neural stem cells. Physiol Rev 2011; 91:1281-304. [PMID: 22013212 PMCID: PMC3552310 DOI: 10.1152/physrev.00032.2010] [Citation(s) in RCA: 171] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Regenerative processes occurring under physiological (maintenance) and pathological (reparative) conditions are a fundamental part of life and vary greatly among different species, individuals, and tissues. Physiological regeneration occurs naturally as a consequence of normal cell erosion, or as an inevitable outcome of any biological process aiming at the restoration of homeostasis. Reparative regeneration occurs as a consequence of tissue damage. Although the central nervous system (CNS) has been considered for years as a "perennial" tissue, it has recently become clear that both physiological and reparative regeneration occur also within the CNS to sustain tissue homeostasis and repair. Proliferation and differentiation of neural stem/progenitor cells (NPCs) residing within the healthy CNS, or surviving injury, are considered crucial in sustaining these processes. Thus a large number of experimental stem cell-based transplantation systems for CNS repair have recently been established. The results suggest that transplanted NPCs promote tissue repair not only via cell replacement but also through their local contribution to changes in the diseased tissue milieu. This review focuses on the remarkable plasticity of endogenous and exogenous (transplanted) NPCs in promoting repair. Special attention will be given to the cross-talk existing between NPCs and CNS-resident microglia as well as CNS-infiltrating immune cells from the circulation, as a crucial event sustaining NPC-mediated neuroprotection. Finally, we will propose the concept of the context-dependent potency of transplanted NPCs (therapeutic plasticity) to exert multiple therapeutic actions, such as cell replacement, neurotrophic support, and immunomodulation, in CNS repair.
Collapse
Affiliation(s)
- Gianvito Martino
- Institute of Experimental Neurology, Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy.
| | | | | | | |
Collapse
|
24
|
Saxena S, Caroni P. Selective neuronal vulnerability in neurodegenerative diseases: from stressor thresholds to degeneration. Neuron 2011; 71:35-48. [PMID: 21745636 DOI: 10.1016/j.neuron.2011.06.031] [Citation(s) in RCA: 389] [Impact Index Per Article: 29.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/27/2011] [Indexed: 12/12/2022]
Abstract
Neurodegenerative diseases selectively target subpopulations of neurons, leading to the progressive failure of defined brain systems, but the basis of such selective neuronal vulnerability has remained elusive. Here, we discuss how a stressor-threshold model of how particular neurons and circuits are selectively vulnerable to disease may underly the etiology of familial and sporadic forms of diseases such as Alzheimer's, Parkinson's, Huntington's, and ALS. According to this model, the intrinsic vulnerabilities of neuronal subpopulations to stressors and specific disease-related misfolding proteins determine neuronal morbidity. Neurodegenerative diseases then involve specific combinations of genetic predispositions and environmental stressors, triggering increasing age-related stress and proteostasis dysfunction in affected vulnerable neurons. Damage to vasculature, immune system, and local glial cells mediates environmental stress, which could drive disease at all stages.
Collapse
Affiliation(s)
- Smita Saxena
- Friedrich Miescher Institut, Novartis Research Foundation, CH-4058 Basel, Switzerland
| | | |
Collapse
|
25
|
A conceptual revolution in the relationships between the brain and immunity. Brain Behav Immun 2011; 25:817-9. [PMID: 21187141 PMCID: PMC3074045 DOI: 10.1016/j.bbi.2010.12.015] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2010] [Accepted: 12/20/2010] [Indexed: 12/15/2022] Open
|
26
|
Ron-Harel N, Cardon M, Schwartz M. Brain homeostasis is maintained by "danger" signals stimulating a supportive immune response within the brain's borders. Brain Behav Immun 2011; 25:1036-43. [PMID: 21182929 DOI: 10.1016/j.bbi.2010.12.011] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2010] [Revised: 12/09/2010] [Accepted: 12/10/2010] [Indexed: 12/23/2022] Open
Abstract
An organism's behavior is determined by the way it senses and perceives the surrounding environment, and by its responses to these stimuli. The major factors known to affect the behavioral response to an event are genetic background, environmental factors, and past experiences, and their imprinting on the relevant brain circuits. Recently, circulating immune cells were introduced as novel players into this system. It was proposed that the brain and circulating immune cells engage in a continuous dialogue that takes place within the brain's territory, though outside the parenchyma (occurring within the brain's borders - the choroid plexi, the brain meninges and the cerebrospinal fluid (CSF)). The cytokines secreted by activated leukocytes residing at the borders were shown to affect neurotrophic factors production within the parenchyma. Here, we suggest that such a dialogue is stimulated at the brain's borders, upon need, by a "danger" signal that originates in the parenchyma in response to any destabilizing event, and discuss the potential role of reactive oxygen species (ROS) in transmitting this signal. Accordingly, a failure to restore balance is likely to lead to aberrant responses to subsequent events. This view thus supports the contention that circulating immune cells are required to maintain the brain's balanced activity and suggests a novel mechanism whereby the surveying immune cells are sensing the brain's status and needs.
Collapse
Affiliation(s)
- Noga Ron-Harel
- Department of Neurobiology, The Weizmann Institute of Science, Rehovot 76100, Israel
| | | | | |
Collapse
|
27
|
Haley GE, Urbanski HF, Kohama SG, Messaoudi I, Raber J. Spatial Memory Performance Associated with Measures of Immune Function in Elderly Female Rhesus Macaques. Eur Geriatr Med 2011; 2:117-121. [PMID: 21603071 PMCID: PMC3097089 DOI: 10.1016/j.eurger.2011.01.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
We recently reported that in aged female rhesus macaques, spatial learning and memory correlates with circadian sleep-wake measures and hippocampal muscarinic type 1 (M(1)) receptor binding. To investigate if spatial memory also correlates with measures of immune function, we now assessed the magnitude of the adaptive immune response to vaccination in the same old female rhesus macaques. Cognitively characterized animals were classified as good spatial performers (GSP) or poor spatial performers (PSP) based on performance in the Spatial Foodport maze. The GSP group had higher frequency of CD8, but not CD4, interferon-γ (IFN-γ) producing cells following vaccination compared to the PSP group, suggesting a stronger CD8 T cell response in the GSP group. In addition, the number of CD-8 IFN-γ positive cells correlated with measures of sleep quality. Interestingly, the PSP group had a significantly higher antibody titer compared to the GSP group, and antibody titer negatively correlated with day-time activity. Thus, in aged female rhesus macaques, superior cognitive performance is correlated with a more robust CD8 T cell response but a reduced antibody response to vaccination.
Collapse
Affiliation(s)
- Gwendolen E. Haley
- Department of Behavioral Neuroscience, Oregon Health and Science University, Portland, OR 97239
- Division of Neuroscience Oregon National Primate Research Center, Beaverton, OR 97006
| | - Henryk F. Urbanski
- Department of Behavioral Neuroscience, Oregon Health and Science University, Portland, OR 97239
- Division of Neuroscience Oregon National Primate Research Center, Beaverton, OR 97006
- Department of Physiology and Pharmacology, Oregon Health and Science University, Portland, OR 97239
| | - Steven G. Kohama
- Division of Neuroscience Oregon National Primate Research Center, Beaverton, OR 97006
| | - Ilhem Messaoudi
- Division of Neuroscience Oregon National Primate Research Center, Beaverton, OR 97006
- Division of Pathobiology and Immunology, Oregon National Primate Research Center Vaccine and Gene Therapy Institute, Beaverton, OR 97006
| | - Jacob Raber
- Department of Behavioral Neuroscience, Oregon Health and Science University, Portland, OR 97239
- Division of Neuroscience Oregon National Primate Research Center, Beaverton, OR 97006
- Department of Neurology, Oregon Health and Science University, Portland OR 97239
| |
Collapse
|
28
|
|
29
|
Schwartz M, Shechter R. Systemic inflammatory cells fight off neurodegenerative disease. Nat Rev Neurol 2010; 6:405-10. [DOI: 10.1038/nrneurol.2010.71] [Citation(s) in RCA: 174] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
|
30
|
|
31
|
Schwartz M, Shechter R. Protective autoimmunity functions by intracranial immunosurveillance to support the mind: The missing link between health and disease. Mol Psychiatry 2010; 15:342-54. [PMID: 20332793 DOI: 10.1038/mp.2010.31] [Citation(s) in RCA: 103] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Circulating immune cells support hippocampal neurogenesis, spatial memory, expression of brain-derived neurotrophic factor, and resilience to stress. Nevertheless, considering the immune privileged status of the central nervous system (CNS), such cells were assumed to be excluded from the healthy brain. It is evident, however, that the CNS is continuously surveyed by leukocytes, though their function is still a mystery. Coupling this routine leukocyte trafficking with the function attributed to circulating T cells in brain plasticity led us to propose here that CNS immunosurveillance is an integral part of the functioning brain. Anatomical restriction of selected self-recognizing leukocytes to the brain's borders and fluids (cerebrospinal fluid) not only supports the brain's activity, but also controls the potential aggressiveness of such cells. Accordingly, the brain's 'privilege' is its acquisition of a private peripheral immunological niche under its own control, which supports brain function. Immune malfunction may comprise a missing link between a healthy and diseased mind.
Collapse
Affiliation(s)
- M Schwartz
- The Department of Neurobiology, The Weizmann Institute of Science, Rehovot 76100, Israel.
| | | |
Collapse
|
32
|
Peres A, Lerias AG, de Aguiar AKK, Silva AO, Costa CB, Bemfica C, de Vargas DM, Andrade DDS, Engelke DS, Pires ENS, Furtado GV, Erpen GL, De Nardin J, Otton LM, Tortorelli LS, da Rosa PM, Chies JAB. As time goes by ... would CD4+ T cells depletion induce early immunosenescence in HIV infected patients? Med Hypotheses 2009; 74:208-9. [PMID: 19699037 DOI: 10.1016/j.mehy.2009.07.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2009] [Accepted: 07/08/2009] [Indexed: 11/30/2022]
|